Change of numerical basis.
Introduction to Logic Gates.
Multiplexer: represented as a trapezoid
$\mathrm{out} = (\mathrm{ip1})\bar{(\mathrm{select})} + (\mathrm{ip2})(\mathrm{select})$
We can make a multiplexer with logic gates (use the equation above)
Discussion of Logism, making a multiplexer